Improvement in slate-frames



a tlnited l W waeeaaw www WILLIAM N. BAR'IHOLOMEW, OF NEWTON,MASSACHUSETTS,

Letters Patent No. 86,272, dated Januar/ry 26, 1869.

INIPROVEMENT IN' SLATE-FRAM'ES.

The Schedule referred to in these Letters Patent and making paxt of thesame.

To whom 'it mtl/y concern:

Be it known that I, WILLIAM N. BARTHOLOMEW, of' Newton, in the county ofMiddlesex, and State ot' Massachusetts, have invented certain new anduseful Improvements in' Slates; and I hereby declare the fol-v lowing tobe a full, clear, and exact description of the same, reference being hadto the accompanying drawings, in which-- Figure 1 is a perspective viewof a slate, made in accordance with my invention, showing the positionwhich the examples to be copied occupy when they are in use.

Figure 2 is a side View of the same, exhibiting more clearly theposition of the copy-cards with relation to the eye of the pupil orcopyist.

My invention' relates to the attachment to a slate of cards containingthe examples or ligures to be reproduced upon the slate by the copyist;and

Its object is to combine the cards with the slate, in such manner that,rst, no part of the slate-surface will be occupied by the copy-card;second, the cardsurface Will be placed perpendicularly, or nearly so, tothe plane of vision of the copyist.

It is manifestly advantageous to leave the slate-surface free anduncovered, -so that the Whole may, as far as possible, he utilized; and,againby placing the card so that its plane shall be about perpendicularto the plane of vision, the oopyist is enabled to see the true form ofthe outline of the figure to be copied. When the copy lies flat on theslate or desk, it is viewed obliquely, and hence is seen in perspective.Vertical lines in the copy will appear distorted by foreshortenlng.

The manner in which my invention is or may be carried into eieet will bereadily understood by reference to the accompanying drawings, in Which`A represents the slate proper;

B, the slate-frame; and

C, the case containing the copy-cards.

In order to have the slate-surface entirely unoccupied, and to hold thecopy-cards at the required angle with respect to the slate, I form inthe frame a slot, et, Whose sides are out, so yas to stand at the angledesired. In this slot, the case O is inserted, and stands, its degree ofObliquity being governed by the inclinar -tion of the sides of the slot.In practice, itwill be found best to make the angle of inclination fromone hundred and twenty'toone hundred and thirty degrees, but of course'it may be varied, according to circumstances. i

In case but one copy-card is to be held in the slate at a time, anarrow' slot, such as represented at b, may he made, in which thelower-edge of the card is insorted.

Again, if the frame or case O, which supports the cards, be made of Woodor other stiff` material, the slot a may have perpendicular sides, andthe case may be provided with a bottom ledge or ange, withperpendicularsides also, which will iit in the slot, the case in thisinstance being set at the required angle to its ange or base, iu orderto give it the necessary obliquity.

Having now described my invention, and the manner in which the same isor may be carried into effect,

What I claim, and desire to secure'by Letters Patent, is-

The formation, in the slate-frame, of slots to receive p and holdinposition the copy-card or cards, or tlie frame which supports the same,substantially as and for thev purposes herein shown and set forth.

In testimony whereof, I have signed my name to this specification,before two subscribing Witnesses.

. WM. N. BAR'IHOLOMEW.

Witnesses: l

GEO. T. ANGELL,

Y CHAs. H. Lover-Jun.

